Typically it's from the Nickel content. I believe most stainless steels are usually 10-14% nickel. Nickel likes to cool really quick and thats where the warpage usually comes from. We run into it all the time in jewelry with high nickel gold alloys. I don't have much experience in welding stainless steel but in other forms of high nickel stuff I know there's usually more pre-bending to combat warpage.
"Your welds should sound like bacon. If your welds smell like bacon, you're on fire." - Uncle Bumblefuck (AvE)
Yup.. The large Nickel and Chromium content of most stainless steels bumps the coefficient of thermal expansion of these up to (and over) the level of something like pure copper.
Combined with the relatively low heat-conductivity of many stainless steel types you can quickly end up with a very large temperatue gradient over a short distance while welding and corresponding expansion across the gradient.
If not kept in check this localised high expansion will rapidly deform the base material (eg. warping sheets) or cause high stresses as the material cools and shrinks again and starts to 'pull' on any welds causing cracks once it's cooled.
And that's even disregarding all the fun stuff that happens in the weld pool and the HAZ with chromium and nickel coming out of solution and reacting with carbon forming carbides and basically making it no longer 'stainless' when things are getting overheated
Bye, Arno.
Combined with the relatively low heat-conductivity of many stainless steel types you can quickly end up with a very large temperatue gradient over a short distance while welding and corresponding expansion across the gradient.
If not kept in check this localised high expansion will rapidly deform the base material (eg. warping sheets) or cause high stresses as the material cools and shrinks again and starts to 'pull' on any welds causing cracks once it's cooled.
And that's even disregarding all the fun stuff that happens in the weld pool and the HAZ with chromium and nickel coming out of solution and reacting with carbon forming carbides and basically making it no longer 'stainless' when things are getting overheated
Bye, Arno.